<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div id="app">
        <input type="button" value="add" @click="add">
        <input type="button" value="del" @click="remove">
          <ul>
              <li v-for="(it,index) in arr" :title="it"> 
                 {{index+1}}城市{{it}}
              </li>
          </ul>
    </div>
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
    <script>
        var app =new Vue({
            el:"#app",
            data:{
                arr:["北京","上海","广州"]

            },
            methods:{
                add:function(){
                    this.arr.push("武汉");
                },
                remove:function(){
                    this.arr.shift();
                }
            }
        })
    </script>
</body>
</html>